Vulnerability-Lookup

GHSA-MF77-27MV-MHM4

Vulnerability from github – Published: 2026-01-21 18:30 – Updated: 2026-01-23 21:30

Details

ProFTPD 1.3.7a contains a denial of service vulnerability that allows attackers to overwhelm the server by creating multiple simultaneous FTP connections. Attackers can repeatedly establish connections using threading to exhaust server connection limits and block legitimate user access.

Severity ?

7.5 (High)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

8.7 (High)


                  
                    CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Show details on source website

JSON

To clipboard

{
  "affected": [],
  "aliases": [
    "CVE-2021-47865"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-770"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-01-21T18:16:18Z",
    "severity": "HIGH"
  },
  "details": "ProFTPD 1.3.7a contains a denial of service vulnerability that allows attackers to overwhelm the server by creating multiple simultaneous FTP connections. Attackers can repeatedly establish connections using threading to exhaust server connection limits and block legitimate user access.",
  "id": "GHSA-mf77-27mv-mhm4",
  "modified": "2026-01-23T21:30:42Z",
  "published": "2026-01-21T18:30:31Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2021-47865"
    },
    {
      "type": "WEB",
      "url": "https://github.com/proftpd/proftpd/issues/1298"
    },
    {
      "type": "WEB",
      "url": "https://github.com/proftpd/proftpd"
    },
    {
      "type": "WEB",
      "url": "https://www.exploit-db.com/exploits/49697"
    },
    {
      "type": "WEB",
      "url": "https://www.vulncheck.com/advisories/proftpd-a-remote-denial-of-service"
    },
    {
      "type": "WEB",
      "url": "http://www.proftpd.org"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
      "type": "CVSS_V4"
    }
  ]
}

CVE-2021-47865 (GCVE-0-2021-47865)

Vulnerability from cvelistv5 – Published: 2026-01-21 17:27 – Updated: 2026-01-23 18:57

Title

ProFTPD 1.3.7a - Remote Denial of Service

Summary

Severity ?

8.7 (High)


                        
                          CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

7.5 (High)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CWE

CWE-770 - Allocation of Resources Without Limits or Throttling

Assigner

VulnCheck

References

URL

Tags

	https://www.exploit-db.com/exploits/49697	exploit
	http://www.proftpd.org/	product
	https://github.com/proftpd/proftpd/issues/1298	issue-tracking
	https://www.vulncheck.com/advisories/proftpd-a-re…	third-party-advisory

Impacted products

	Vendor	Product	Version
	ProFTPD	ProFTPD	Affected: 1.3.7a

Credits

xynmaps

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2021-47865",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-01-22T21:57:47.199556Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-01-22T21:57:57.241Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "ProFTPD",
          "vendor": "ProFTPD",
          "versions": [
            {
              "status": "affected",
              "version": "1.3.7a"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "xynmaps"
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
              "value": "\u003cp\u003eProFTPD 1.3.7a contains a denial of service vulnerability that allows attackers to overwhelm the server by creating multiple simultaneous FTP connections. Attackers can repeatedly establish connections using threading to exhaust server connection limits and block legitimate user access.\u003c/p\u003e"
            }
          ],
          "value": "ProFTPD 1.3.7a contains a denial of service vulnerability that allows attackers to overwhelm the server by creating multiple simultaneous FTP connections. Attackers can repeatedly establish connections using threading to exhaust server connection limits and block legitimate user access."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "Automatable": "NOT_DEFINED",
            "Recovery": "NOT_DEFINED",
            "Safety": "NOT_DEFINED",
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "attackVector": "NETWORK",
            "baseScore": 8.7,
            "baseSeverity": "HIGH",
            "exploitMaturity": "NOT_DEFINED",
            "privilegesRequired": "NONE",
            "providerUrgency": "NOT_DEFINED",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "valueDensity": "NOT_DEFINED",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "HIGH",
            "vulnConfidentialityImpact": "NONE",
            "vulnIntegrityImpact": "NONE",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
          },
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ]
        },
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 7.5,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "NONE",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
            "version": "3.1"
          },
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ]
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-770",
              "description": "Allocation of Resources Without Limits or Throttling",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-01-23T18:57:32.039Z",
        "orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
        "shortName": "VulnCheck"
      },
      "references": [
        {
          "name": "ExploitDB-49697",
          "tags": [
            "exploit"
          ],
          "url": "https://www.exploit-db.com/exploits/49697"
        },
        {
          "name": "ProFTPD Official Website",
          "tags": [
            "product"
          ],
          "url": "http://www.proftpd.org/"
        },
        {
          "name": "ProFTPD GitHub Repository",
          "tags": [
            "issue-tracking"
          ],
          "url": "https://github.com/proftpd/proftpd/issues/1298"
        },
        {
          "name": "VulnCheck Advisory: ProFTPD 1.3.7a - Remote Denial of Service",
          "tags": [
            "third-party-advisory"
          ],
          "url": "https://www.vulncheck.com/advisories/proftpd-a-remote-denial-of-service"
        }
      ],
      "source": {
        "discovery": "UNKNOWN"
      },
      "title": "ProFTPD 1.3.7a - Remote Denial of Service",
      "x_generator": {
        "engine": "vulncheck"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
    "assignerShortName": "VulnCheck",
    "cveId": "CVE-2021-47865",
    "datePublished": "2026-01-21T17:27:44.167Z",
    "dateReserved": "2026-01-18T12:35:05.170Z",
    "dateUpdated": "2026-01-23T18:57:32.039Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

Action not permitted

GHSA-MF77-27MV-MHM4

CVE-2021-47865 (GCVE-0-2021-47865)

Tags

Sightings

Nomenclature